Desktop startup proof: 30-second event-loop stall on first POST /oauth/token.
Linux Electron under Xvfb; 1280x900; light theme; fresh isolated state; no clicks.

BASE
0.000s token-stall-start
30.000s token-stall-end
10.000s clientRuntime.authorization.bootstrapRemoteBearerSession: Failure; duration=10005.3ms
14.999s clientRuntime.authorization.bootstrapRemoteBearerSession: Interrupted; duration=4498.4ms
15.000s desktop.localEnvironmentAuth.getBearerToken: Failure; duration=17575.0ms
25.024s clientRuntime.authorization.bootstrapRemoteBearerSession: Failure; duration=10002.2ms
30.023s clientRuntime.authorization.bootstrapRemoteBearerSession: Interrupted; duration=4498.1ms
30.023s desktop.localEnvironmentAuth.getBearerToken: Failure; duration=15001.3ms
Final screenshot difference vs screenshot 500ms earlier (pixels): 0

HEAD
0.000s token-stall-start
30.000s token-stall-end
10.000s clientRuntime.authorization.bootstrapRemoteBearerSession: Failure; duration=10006.9ms
20.502s clientRuntime.authorization.bootstrapRemoteBearerSession: Failure; duration=10001.7ms
30.031s clientRuntime.authorization.bootstrapRemoteBearerSession: Success; duration=9027.9ms
30.031s desktop.localEnvironmentAuth.getBearerToken: Success; duration=32452.3ms
Final screenshot difference vs screenshot 500ms earlier (pixels): 0